There’s a reason marijuana laws don’t work: There is no compelling reason for them to work.

Marijuana is not a dangerous drug. Used in moderation, cannabis has few ill effects; used in excess, the intoxicant has fewer and less severe side effects than alcohol. It’s not in a class with opioids that can kill users. There has been no known lethal human overdose of marijuana. The California Medical Association supports state Proposition 64, which would legalize, tax, and regulate marijuana for recreational adult use. There is no compelling public-safety interest in government’s ban on adult recreational use — not in a free country.

It’s time for California to cut its ties with ill-conceived federal and state drug laws that ban adult recreational use and thus consign marijuana cultivation and sale to criminal gangs. Just as the mob grew powerful thanks to the American prohibition of alcohol (which failed to douse the public’s desire for spirits), drug gangs have flourished thanks to Washington’s war on drugs. By legalizing marijuana, not simply decriminalizing its use, California can move the trade out of the shadows to a place where the state can regulate and tax it. As Lt. Gov. Gavin Newsom, a proponent, told the San FranciscoChronicle’s editorial board, “The goal is to end the black market.”

Criminalization of marijuana also feeds a public contempt toward the political system. When they were young, Presidents Obama, George W. Bush and Bill Clinton flouted the law, partook of the weed and got away with it. If they had been arrested and convicted, their life paths may not have led to the White House. An arrest on drug charges can prevent young men and women from winning security clearances needed for some jobs but not, apparently, for the position of commander in chief. Alas, when Clinton, Bush, and Obama were in a position to do something — to end a crusade that disproportionately hurts young people of color — they could not be bothered.

In that spirit, many statewide officeholders in California (including Newsom) refused in 2010 to endorse Proposition 19, which would have legalized adult use of marijuana. Then Colorado and Washington legalized recreational use in 2012 and it became clear California would follow suit. Newsom saw the light. He and political operative Jason Kinney now frame marijuana legalization as a “social justice” issue — yet it remains a social justice issue from which most Democrats run. No other statewide officeholder has endorsed Prop. 64, although Gov. Jerry Brown, who trashed Prop. 19, teased the editorial board this month by offering that he was “mulling” the 2016 ballot measure.

Let me be clear. In 2016, Californians don’t go to prison — or even jail — for holding small quantities of marijuana. (Possession of less than an ounce of marijuana isn’t even a misdemeanor in California anymore — it’s an infraction, punishable by a $100 fine. Prop. 64 would require that minors caught with an ounce or less attend drug education or counseling programs and perform community service.) State laws against marijuana were wrong when they led to jail time; now that getting caught can end with a $100 ticket, they’re a waste of resources and feckless.

Rep. Eric Swalwell, D-Dublin, has endorsed Prop. 64. As a former prosecutor, Swalwell need not fear being labeled soft on crime. In 2014, I asked him if he thought legalization would drive up usage. Swalwell answered, “Honestly, no.” Newsom has been careful to frame himself as not pro-marijuana as much as anti-Prohibition. He knows that laws against pot are not the only threat to teenagers; heavy marijuana use can change the structure of their brains and sabotage their success as adults.

As the Prop. 64 meeting ended, Newsom told me how much his wife and he hate secondhand marijuana smoke. As the election looms, readers have sent me the occasional email warning that legalizing pot could increase squalor on the streets of San Francisco. They warn that with legalization, downtown could smell like pot smoke — as if it does not already. Yes, San Francisco has more than its share of medical marijuana dispensaries. Sorry, esteemed reader, I answer, booze and heroin are the downward drivers on San Francisco sidewalks, not marijuana. Pot plumes work like the fog that comes in on little cat feet and cools the bay, except it brings relief to the nose. In a city that reeks of urine and the pungent smell of stagnant sewers, marijuana smoke has become San Francisco’s deodorant.